Peruvian Kent is the only choice of mango at the moment. Due to sea-freighting, the variety often proves uninspiring to eat, but we are now in the latter half of the season and there are some very good, flavoursome fruit to be found. Ripe-and-ready twin-packs tend to be a good choice for quality (although you still often have to wait several days for good softness), but plump loose mangoes, as long as they are not hard-green, should also deliver satisfaction (at a very reasonable price).
Finding the Tastiest Fruit in UK